Fair use means you can talk about Kleenex® when referring to a box of facial tissue. You can say Kleenex®, you can write Kleenex®, you can write about Kleenex® you can make a painting of a box of Kleenex®.
However, you cannot put their logo on anything else. You cannot make T-shirts with Kleenex brand. You cannot make prints of the painting (above) and sell them.
Basically, you may not use their logo in anything mass produced. Fair use means that you can use it once, in almost any way. If you couldn't, then it would be like preventing you from saying "Kleenex®" But, using it for anything other than talking about it, especially anything where you will make money from it, is a breach of copy-right.